LINCOLN, Neb. (AP) — No new cases of bird flu were found in Nebraska over the past week, but state officials say 900,000 more chickens will be slaughtered to limit the spread of the disease.

The Nebraska Agriculture Department said Tuesday the company that owns several farms where bird flu has been found agreed to kill the chickens on two other farms it owns in Dixon County as a precaution.

Including the new farms, nearly 5 million chickens are being destroyed on farms in northeast Nebraska to help control the bird flu.

Another farm in nearby Knox County with 3 million chickens remains under quarantine, but tests have not confirmed the presence of bird flu.

Nationwide, the virus has led to 47 million dead birds — mostly turkeys and egg-laying chickens.